summaryrefslogtreecommitdiff
path: root/open_issues/gnumach_integer_overflow.mdwn
diff options
context:
space:
mode:
authorThomas Schwinge <tschwinge@gnu.org>2013-07-10 23:39:29 +0200
committerThomas Schwinge <tschwinge@gnu.org>2013-07-10 23:39:29 +0200
commit9667351422dec0ca40a784a08dec7ce128482aba (patch)
tree190b5d17cb81366ae66efcf551d9491df194b877 /open_issues/gnumach_integer_overflow.mdwn
parentb8f6fb64171e205c9d4b4a5394e6af0baaf802dc (diff)
IRC.
Diffstat (limited to 'open_issues/gnumach_integer_overflow.mdwn')
-rw-r--r--open_issues/gnumach_integer_overflow.mdwn35
1 files changed, 34 insertions, 1 deletions
diff --git a/open_issues/gnumach_integer_overflow.mdwn b/open_issues/gnumach_integer_overflow.mdwn
index 2166e591..08a29268 100644
--- a/open_issues/gnumach_integer_overflow.mdwn
+++ b/open_issues/gnumach_integer_overflow.mdwn
@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2012 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2012, 2013 Free Software Foundation, Inc."]]
[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -15,3 +15,36 @@ License|/fdl]]."]]"""]]
<braunr> yes, we have integer overflows on resident_page_count, but
luckily, the member is rarely used
+
+See also [[gnumach_vm_object_resident_page_count]].
+
+
+## IRC, freenode, #hurd, 2013-06-04
+
+ <elmig> this is declared as int on vm_object.h
+ <elmig> and as it as counter it's always positive
+ <braunr> yes it should be unsigned
+ <elmig> ok
+ <braunr> but leave it as it is for consistency with the rest
+ <elmig> i send patch :)
+ <braunr> please no
+ <braunr> unless you've fully determined the side effects
+ <elmig> i've grepped the vars and saw only comparisons > and = 0
+ <elmig> never less than 0
+ <braunr> > 0 is the same
+ <braunr> well
+ <braunr> > not, but >= would be a problem
+ <elmig> http://paste.debian.net/plain/8527
+ <elmig> asctually no >=0
+ <braunr> still, i don't want to change that unless it's strictly necessary
+ <braunr> hum, you're grepping ref_count, not resident_page_count
+ <elmig> i did both
+ <elmig> on resident_page_count theres resident_page_count >= 0
+ <elmig> = 0, == 0
+ <braunr> this isn't the only possible issue
+ <braunr> anyway
+ <braunr> for now there is no reason to change anything unless you do a full
+ review
+ <elmig> only place i see resdent_page_count and page_count being decreased
+ it's on vm/vm_resident.c
+ <elmig> vm_page_remove() and vm_page_replace()